docs: def free_function(
              self,
              name=None,
              function=None,
              return_type=None,
              arg_types=None,
              header_dir=None,
              header_file=None,
              recursive=None):
          """
          Returns reference to free function declaration that matches
          a defined criteria.
  
          """
  
          return (
              self._find_single(
                  scopedef.scopedef_t._impl_matchers[namespace_t.free_function],
                  name=name,
                  function=function,
                  decl_type=self._impl_decl_types[namespace_t.free_function],
                  return_type=return_type,
                  arg_types=arg_types,
                  header_dir=header_dir,
                  header_file=header_file,
                  recursive=recursive)
          )